Digital Rights Management (DRM) refers to techniques that are used to protect content, such as by controlling or restricting the use of digital media content on electronic devices. One characteristic of DRM is that it can bind the media content to a given machine or device. Thus, a license that pertains to a particular piece of content and which defines rights and restrictions associated with the piece of content will typically be bound to the given machine or device. As a result, a user will not typically be able to take the piece of content and move it to another machine in order to playback the content.
Another characteristic of some DRM-protected content is that some content types, such as ASF files, allow only one set of rights and restrictions, i.e. “policies”, to apply to the entire file. For example, when a video file is rendered, either Macrovision may be required to be enabled on an analog video output for the whole file, or it may not be required at all. With these particular types of files, one cannot change the policies associated with the content in the middle of the file or mid-stream.